Figure 3
Multiple sequence alignment of Aca s 4 with other α-amylases of mite origin and human α-amylase. Aca s 4: Acarus siro (GenBank: ABL09312); Tyr p 4: Tyrophagus putrescentiae (GenBank: ABM53754); Blo t 4: Blomia tropicalis (GenBank: AAQ24543) [12]; Eur m 4: Euroglyphus maynei (GenBank: AAD38943) [13]; Der p 4: Dermatophagoides pteronyssinus (GenBank: AAD38942) [13]; HPA: human pancreatic α-amylase (GenBank: AAH07060). The sequence similarities to Aca s 4 are 74%, 70%, 64%, 66%, and 50%, respectively. Full-length sequences of mature proteins are aligned. Amino acids identical to those of Aca s 4 are shaded. In the Aca s 4 sequence, the N-terminal sequence determined by Edman sequencing (dotted underline) and fragments determined by LC-MS/MS analysis (solid underline) are indicated. Positions of catalytic residues (@) and residues binding the Cl- (#) and the Ca2+ (*) are marked. N-glycosylation signals are double underlined (Aca s 4 and Blo t 4 have no predicted N-glycosylation sites). Note the Asn295Ser mutation located in the Cl- -binding site of mite α-amylases (compared to HPA and other animal α-amylases). Cys residues forming four conserved disulfide bridges (‡) and one specific disulfide (+) in the Aca s 4 molecule are marked.